Briggs is listed as day-to-day but was seen wearing a cast Sunday, and ankle injuries can be tricky. Safety Craig Steltz, for instance, hasn’t practiced since the first preseason game because of an ankle sprain. Making matters worse, backup linebacker Nick Roach hasn’t played or practiced in two weeks after undergoing arthroscopic knee surgery. Roach, who plays all three linebacker spots, is expected back for Week 1, though. Brian Iwuh will fill in for Briggs for now.

After a preseason in which the first-team defense has struggled mightily on third down, Briggs’ absence would be huge because none of the other linebackers are as adept in pass coverage or blitzing as him and Brian Urlacher, who is coming off his own calf injury but should be ready for Week 1.